Preparation of alkylated aromatic sulphonic acids



Patented 18, 1938 UNITED STATES PATENT OFFICE PREPARATION OF ALKYLATED AROMATIC SULPHONIC ACIDS of New York No Drawing. Application January 17, 1936, Serial No. 59,548

. 7 Claims.

The present invention relates to a process for preparing alkylated naphthalene sulphonic acids and their salts and it particularly relates to a process of preparing novel alkylated naphthalene sulphonic acids and compositions thereof containing between 4 to 8 carbon atoms in the alkyl group.

Although not specifically limited thereto, the present invention will be illustratively described in connection with the production of mono-alkyl, alpha naphthalene sulphonic acids although it is to be understood that the present invention is also applicable to the production of other alkylated sulphonic acids than those specifically described.

It is among the objects of the present invention to provide an improved process for preparing alkylated naphthalene sulphonic acids and their compounds for use as penetrating and wetting out agents and which will be of high stability and substantial resistance to acids, and calcium and magnesium salts.

It is another object of the present invention to prepare alkylated naphthalene sulphonic acids and their compoundswith high yield and without the production of undesirable Icy-products which acids are particularly useful incarbonizing', in dye baths, in bleaching operations and for inclusion for soaping, scouring and detergent mixtures.

A further'object of the present invention is to prepare improved alkylated naphthalene sulphonic acids and their salts which may be directly utilized as penetrating and wetting out agents without requiring an expensive and diiiicultpurification process and which preparations may be readily shipped, stored and utilized.

' Other objects will be obvious and will appear during the course of the present specification.

In accomplishing the above objects it has been found that naphthalene may be successfully alkylated and sulphonated with high yields and may be maintained between 90 to 130 C. with a preferred range between 100 to 120 C. and for a time range of from 1 to hours, with a preferred range of from 2 to 3 hours.

In the second sulphonation operation, the tem- 5 perature is preferably maintained well below 70 C. with a preferred range of 40 to 50 C. and for a. relatively long time say for more than hours and preferably for less than 20'to 25 hours.

In the second operation it is most desirable to 0 utilize a mixture of concentrated sulphuric acid and oleum .which will assure substitution of a sulphonic acid group in the naphthalene nucleus.

It appears as a result of the above process that only one alkyl group enters the nucleus. The exact position of this alhl group has not been definitely determined.

It also appears as a result of the above process, that a small amount of the beta acid is formed and this has been found particularly advantageous inasmuch as a combination of a relatively large amount of the alpha with a relatively small amount of the beta acid is most stable and effective.

As an example of one method of carrying out the invention, naphthalene and secondary butyl carbinol in equimolecular portions are combined together in the presence of a large excess of concentrated sulphuric acid at a temperature of 100 to 120 .C. for a time of approximately 1 to 3 hours.

For example, 130 parts by weight of naphthalene and 88 parts of secondary butyl carbinol are mixed together and 385 parts of 66 B. sulphuric acid are added.

The mixture is gradually heated until the temperature reaches 100 C.

When the reaction has been completed the mixture will separate into two layers, the upper layer containing the products of condensation and the lower layer containing a residual acid, which lower layer is drawn oil as waste acid.

The top layer containing the amylated naphthalene is then treated with a mixture of 66 B. sulphuric acid and 20% oleum, the mixture for example being made of 100 parts of sulphuric acid and 100 parts of the oleum.

Sulphonation is carried ,out from 16 to 18 hours at a temperature of from 40 to C.

The resultant sulphonated product is then di- 50 luted with water, say about three times its own volume, and the diluted mixture is treated with parts of freshly sl'aked lime, which will be about sufficient to neutralize the free sulphuric acid. a

penetrative properties and will give a test result of 2 to 3 seconds with a standard sinking test on felt using a 1% solution at F.

The solution is particularly suitable for carbonizing' since it is highly resistant to'5 Tw. sulphuric acid (about 4% by weight) which acid is largely used for carbonizing.

Even after heating at 150-180 F. for several hours there' is no clouding or precipitation.

The compound has a highresistance to calcium chloride and it will stand up to 2 parts of calcium chloride to 1 part of the sulphonic acid.

Other alcohols or mixtures of alcohols may be utilized such as normal butyl alcohol, iso-butyl alcohol, secondary butyl alcohol, normal butyl carbinol, (or normal amyl'alcohol) iso-butyl carbinol, methyl propyl carbinol, diethyl carbinol, dimethyl ethyl carbinol, tertiary amyl alcohol, normal hexyl'alcohol, methyl amyl alcohol, 2- ethyl butyl alcohol and octyl alcohol, (2-ethyl hexanol) The octyl and hexyl alcohols require a somewhat higher proportion of sulphuric acid than the secondary butyl carbinol in the alkylation step.

In the preferred product the beta product forms between 5 to 20% of the sulphonic acid while the alpha ranges from to 80% of the sulphonic acid.

The above process may be illustrated by the following equations:

The sulphonation and/or allgvlation operations described above may, in certain instances, be also applied to alkylation with less than four, or more than eight carbon atoms and/or to the treatment of other cyclic hydrocarbons or heterocyclic materials than naphthalene, such as cyclohexane, pyridine, quinolin, benzene, toluene, xylene, anthracene, phenanthrene, terpenes, (e. g.

pine oil) and so forth, which hydrocarbons may T aisaaea V be made in the preparations, times and temperatures specified above and that the process, as described, may also be described for the sulphonation of other products and it is intended to include all such changes and modifications within the scope of the present invention.

What is claimed is:

1. A process of successively butylating and sulphonating aromatic compounds which comprises butylating the aromatic compounds with a butyl alcohol and with a sulphonating agent successively at decreasing temperatures, the butylation being carried out at a temperature of 90 to 130 C. and the sulphonation being carried out at a temperature of between 30 and 60 C.

2. A process of successively amylating and sulphonating aromatic compounds which comprises amylating aromatic compounds with an amyl alcohol and with a sulphonating agent successively at decreasing temperatures, the amylation being carried out at a temperature of 90 to 130 C. and the sulphonation being carried out at a temperature of between 30 and 60 C.

3. A process of successively alkylating and sulphonating aromatic compounds which comprises treating the aromatic compounds with an alkylating agent and with a sulphonating agent successively at decreasing temperatures, the alkylation being carried out ata temperature of 90 to 130 C. and the sulphonation being carried out at a temperature of between 30 and 60 0., the alkylating agent consisting of one or more aliphatic alcohols having from 4 to 8 carbon atoms.

4. A process of producing mono alkyl alphanaphthalene sulphonic acids which comprises combining naphthalene and an aliphatic alcohol in the presence of sulphuric acid at a temperature of to C. and then increasing the con- I centration of sulphuric acid and sulphonating at a temperature of 40 to 50 C.

5. A process of producing mono alkyl alphanaphthalene sulphonic acids which comprises combining naphthalene and an aliphatic alcohol in the presence of sulphuric acid at a tempera ture of 100 to 120 C. and then increasing the concentration of sulphuric acid and sulphonating at a temperature of 40 to 50 0., said aliphatic alcohol containingfrom 4 to 8 carbon atoms. I V 6. A process of producing mono alkyl alphanaphthalene sulphonic acids which comprises combining naphthalene and an aliphatic alcohol in the presence of sulphuric acid at a temperature of 100 to 120 C. and then increasing the concentration of sulphuric acid and sulphonating at a temperature of 40 to 50 C., said naphthalene 1 and aliphatic alcohol being used in equi-molecular proportions.

7. A process of producing mono alkyl alpha naphthalene sulphonic acid which comprises reacting about equimolecular weights of naphthalene and a lower alkanol having between 4 and 8 carbon atoms together in the presence of sulphuric acid at a temperature between 100 and 120 C. and then reacting the alkylated naphthalene witha sulphonating reagent containing oleum at a temperature between 40 and 50 C. to form the alpha-sulphonic acid.

ALTON A. COO

SWANEE V. VALJAVEC. 

